Radio frequency devices are often used in industrial operations, a common example being the application of dielectric heating to the fabrication of articles employing a hot melt adhesive. Utilization of radio frequency or dielectric energy permits the heating of surfaces remote from the outer surface of the article. However, the use of such radio frequency devices may complicate the design of the apparatus due to the care necessary in designing the power supply leads to the high-frequency load, e.g. the dielectric sealer head. While transmission lines that are somewhat flexible are available to the machine designers, the flexibility thereof is somewhat limited, resulting in either restricted movement of the high-frequency load with respect to the power supply, or requiring significant amounts of maintenance because of the fatigue of the transmission lines.
While examples of non-contacting rotary coupling members for the transmission of radio frequency power have been known, as exemplified by U.S. Pat. Nos. 2,439,235 and 2,944,230, no such non-contacting coupling members are known which permit relative linear motion between the radio frequency load and the power supply. Such a coupler would be of advantage to a machine designer for utilization on such devices as reciprocating dielectric heater elements which can be arranged to follow the article, for example, a linearly moving web, for a period of time necessary to provide a seal thereon and then to reverse its motion to pick up the web at a new location.